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Mechanic Repairing Motorcycle

BATTERY INSPECTION
& MAINTENACE

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  • Check the battery’s state of charge. Most batteries have a State of Charge Indicator on top of the battery that will give you an on the spot diagnosis of the battery condition. However, a more reliable way to check is with a voltmeter to determine the stabilized voltage or if the vent caps are removable a hydrometer to determine the specific gravity (SG) of the electrolyte.

  • Ensure the battery top is clean, dry, and free of dirt and grime. A dirty battery can discharge across the grime on top of the battery casing.

  • Inspect the terminals, screws, clamps and cables for breakage, damage, or loose connections. These should be clean, tight and free of corrosion.

  • Apply a thin coating of high temperature grease to posts and cable connections for added protection.

  • Inspect the battery case for obvious signs of physical damage or warpage. This usually indicates the battery has been overheated or has been overcharged.

  • If you have a maintainable battery, it is important to check if the battery has sufficient electrolyte covering the battery plates. If topping up is required, do not over fill as the fluid levels will rise when the battery is fully charged and may overflow.

  • Top up using distilled or demineralized water and never fill with sulphuric acid.

  • When servicing a sealed maintenance free (SMF) battery, check the State of Charge Indicator. This gives you a snap shot of the battery’s condition and whether the battery needs to be charged or replaced. The vehicle may still start the engine although the indicator outlines to replace the battery.

  • If the State of Charge Indicator advises ‘Replace Battery’ it is important that the battery is replaced as the electrolyte levels may be below the plates which can lead to an internal explosion.

  • For batteries used in seasonal applications and stored long term, fully recharge the battery prior to storing. Check the state of charge or voltage regularly.

  • Should the voltage drop below 12.5V, recharge the battery. It is important to check the battery completely before reconnecting to electrical devices.

  • If you are unsure about the condition or state of charge of the battery, take it to your local Lead acid battery distributor. They can inspect and test your battery and provide you with professional advice and assistance.

  • Battery Testing

  • Battery testing should be considered an integral part of any periodic vehicle maintenance routine and should be performed whether or not a starting problem has occurred.

  • Due to the increased electrical demands on the battery, little warning is given before failure. Pre-emptive battery replacement can help eliminate many of the costs and problems associated with a flat or end of life battery.

  • Before testing a battery, it is important that the battery is fully charged. Even a slightly discharged battery can give a false reading and deem the battery faulty when all that is required is a recharge.

  • There are many different types of testing equipment available. A digital battery tester is the preferred option as they are safe, easy to use and offer a quick diagnosis of the condition of the battery.

  • Fixed and adjustable load testers, voltmeters, hydrometers and discharge testers can also be used, however correct training is required prior to using any of these testers to prevent personal injury or damage to the vehicle.

HYDROMETER

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• The state-of-charge of a lead acid battery can be determined by the specific gravity (SG) of the electrolyte (its density compared to a reference such as water). The SG can be measured directly with a hydrometer or indirectly by the stabilised voltage with a voltmeter. Please note the temperature of the acid affects the result.

DIGITAL BATTERY TESTER/ CONDUCTANCE METER

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  • Microprocessor controlled digital battery testers are easy to use, very safe and can help determine early battery failure. The tester works by transmitting a small signal through the battery that uses measurements of conductance or resistance (impedance) to indicate battery condition.

  • Most models provide battery, starting and charging tests. Printer options enable results to be given to the customer.

LOAD TESTER

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  • Adjustable load testers are a reliable method to determine the starting capacity of a battery as the test applies a real load similar to when cranking the engine. This load however does create a spark risk if leads are connected to corroded or loose terminals.

  • The standard test is to load the battery to 50% of its CCA rating (Cold Cranking Amperes) for 15 seconds. If the voltage reads above 9.6 volts the battery is ok. For example a battery that has a CCA rating of 600 should be tested at 300CCA for 15 seconds.

  • The standard interpretation of the result is that if, at the end of the 15 second test, the loaded voltage reading is between 9.6V and 10.6V then the battery is deemed to be good. If the result is under 9.6V the battery is not good and may not crank the engine. It is always recommended that you check the individual manufacturer’s specifications

BATTERY CHARGING

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  • Charging a lead acid battery is the process of replacing the energy removed during discharge, plus EXTRA to compensate for any charging inefficiencies. The amount of energy necessary for complete recharge depends on the depth of discharge, rate of recharge and temperature.

  • Typically 110% - 150% of the discharged ampere-hours depending on battery type must be returned to the battery to achieve full recharge.

CHARGER SELECTION

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  • Lead acid batteries should be charged in 3 stages; constant current(boost),constant voltage (absorption) and float charge.

  • When choosing a battery charger, it is important to select a charger that delivers the specified charging voltage and current to suit the battery type.

  • Flooded, Absorbed Glass Mat (AGM) and Gel battery types require different charging specifications to provide optimum performance and service life.

  • For manual charger-Voltage setting : Monitoring battery voltage during charging is extremely important to reduce the risk of overcharging and to check the progress of the battery during recharge. Always keep inside the parameters outlined in the below table. Failure to do so can result in permanent damage to the battery.

  • For manual charger-Current setting The recommended safe charging current is 10% of the battery’s 20 hour (Ah) rating.

  • For example if you want to charge a 100Ah battery, the recommended charger current for this battery would be 10 Amps. Slow charging is the best way to recharge a lead acid battery. Fast charging a lead acid battery by increasing the recommended amperes may cause undue stress and shorten battery life.

  • Due to efficiency aspects, the charge amount must be more than the discharged amount. This coefficient factor can be between 110% to 150%.

  • The deeper the discharge, the higher the coefficient factor.

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       Note: Charging must be paused when the temperature rises above 50°C

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              Type(12V).                                                                Absorption Charging                                       Float Charging

       Flooded (Maintainable / SMF)                                          14.4 to 14.8V                                                  13.2 to 13.5V*

       AGM (Absorbed Glass Mat)                                              14.6 to 14.8V                                                  13.8 to 14.0V

       Gel Electrolyte                                                                    14.6 to 14.8V                                                  13.6 to 13.8V

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  • The recommended temperature during charging is 25°C. Charging must be paused if the battery reaches 50°C.

    The above specifications are for 12 volt lead acid batteries. When charging 6 volt batteries, half the voltage specifications provided.

  • In addition to following the battery charging voltage guidelines, selecting the correct charging current (Amps) for the battery size is crucial to provide performance and service life.

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The recharging duration is difficult to determine due to variables such as:

• Depth of discharge
• Temperature
• Size and efficiency of the charger
• Age and condition of the battery
• For a guide, refer to the constant current charging method table

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IMPORTANT NOTE:

Avoid quick charging, as this only charges the surface of the battery plates and can increase the chance of overheating, leading to permanent battery damage.

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FACTORS AFFECTING THE BATTERY LIFE

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  • As batteries age they gradually lose their capacity as their function is performed. The constant charge and discharge eventually leads to failure.

  • Components corrode over time, electrical shorts occur and vibration causes damage; all eventually causing failure.

  • Overcharging and undercharging of a battery will also have a bearing on battery life.

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BATTERY INSPECTION

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  • Check electrolyte level - fluid below the tops of the separators indicates overcharging or poor maintenance.

  • Overcharge condition may be due to incorrect voltage setting, low voltage caused by heat or internal defects, or old age deterioration.

  • Is there electrolyte on the top of the battery? This can indicate overcharging or overfilling.

  • Is the battery loose in the carrier? This can cause failure from vibration.

  • Does the battery have signs of damage or mistreatment? This can also cause failure.

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DISCHARGED BATTERIES (DEAD/FLAT)

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  • A flat battery should be checked with a hydrometer. A low Specific Gravity reading of 1.220 or less in all cells indicates a discharged battery and it must be charged before further examination and testing can occur.

  • The discharged condition may be due to a problem in the electrical system (slipping alternator belt, faulty regulator or alternator, high resistance due to corrosion).

  • Internal shorts may also be due to manufacturing defects or shorts through the ageing process or vibration damage.

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TECHNICAL TIPS TO AVOID BATTERY FAILURE

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  • Normal battery ability to crank the engine. Other less noticeable factors, such as changed driving patterns and colder / hotter weather will all have an effect on the life of a battery. Encourage your customers to ask for a ‘FREE Battery Test’. It’s good public relations and if the battery is near failure, it may avoid the inconvenience of a roadside breakdown.

  • Vibration can reduce a battery’s life. Always use an approved battery clamp to limit vibration. PBL batteries are built tough, using robust internal components to resist damage through abrasion and puncture from vehicle vibration.

  • Many alleged ‘dead batteries’ are merely flat batteries. Drivers simply leave lights on or can have faulty voltage regulators.

  • Ensure your battery is properly tested before replacing a battery.
    It’s impossible to know exactly when a battery might fail. A slow starting engine is sometimes

  • an indication.

  • Old batteries can give trouble in colder weather.

  • Equally, if an engine area becomes overheated in very hot weather and the battery is under strain from air conditioners it may fail. Regular battery checks are always advised.

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